Cadillac 2006 STS - Manual (Page 344)

If No Steam Is Coming From
Your Engine
An overheat warning, along with a CHECK COOLANT
LEVEL message, can indicate a serious problem.
If you get an engine overheat warning with no CHECK
COOLANT LEVEL message, but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get a little too hot when you:
• Climb a long hill on a hot day.
• Stop after high-speed driving.
• Idle for long periods in traffic.
• Tow a trailer.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Set the climate controls to the highest heat setting
and fan speed and open the windows, as necessary.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.
If the warning continues and you have not stopped, pull
over, stop, and park your vehicle right away.
If there is still no sign of steam, you can idle the engine
for three minutes while you are parked. If you still
have the warning, turn off the engine and get everyone
out of the vehicle until it cools down. Also, see
“Overheated Engine Protection Operating Mode” later in
this section.
You may decide not to lift the hood but to get service
help right away.
Overheated Engine Protection
Operating Mode
This operating mode allows your vehicle to be driven to
a safe place in an emergency. Should an overheated
engine condition exist, an overheat protection mode
which alternates firing groups of cylinders helps prevent
engine damage. In this mode, you will notice a loss in
power and engine performance. A low coolant and/or
engine overheat warning will indicate that an overheat
condition exists. Driving extended miles (km) and/or
towing a trailer in the overheat protection mode should
be avoided.
Notice: After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss and change the oil.
See Engine Oil on page 5-18.
5-32